In the paper, the research results on the removal of aliphatic hydrocarbons (C7 to C30) on constructed wetlands have been presented. The research has been realized on the semi-technical scale constructed wetlands. planted with reed Phragmites australis. The experimental installation is located on the filling station in Balice and treats the fraction of stormwater from this utility. The concentrations of total aliphatic hydrocarbons in analyzed stormwater were between 96.02 µg/dm3 and 6177.33 µg/dm3 , and from 47.55 µg/dm3 to 5011.14 µg/dm3 in effluent from the installation. The average total aliphatic hydrocarbons removal effectiveness was 48%, the values ranged from 19% to 81%. Hydrocarbons C14 to C18 were removed with the lowest effectiveness (26%–32%), the lighter hydrocarbons – with higher one (39%–68%), however the highest removal effectiveness were observed for the hydrocarbons with the highest carbon atoms numbers (from 51% for C20 to 92%–93% for C26–C30).
Pyrolysis is potentially an effective treatment of oily sludge for oil recovery, and the addition of a catalyst is expected to affect its pyrolysis behavior. In the present study, Fe/Al-pillared bentonite with various Fe/Al ratios as pyrolysis catalyst is prepared and characterized by XRD, N2 adsorption, and NH3-TPD. The integration of Al and Fe in the bentonite interlayers to form pillared clay is evidenced by increase in the basal spacing. As a result, a critical ratio of Fe/Al exists in the Fe/Al-pillared bentonite catalytic pyrolysis for oil recovery from the sludge. The oil yield increases with respect to increase in Fe/Al ratio of catalysts, then decreases with further increasing of Fe/Al ratio. The optimum oil yield using 2.0 wt% of Fe/Al 0.5-pillared bentonite as catalyst attains to 52.46% compared to 29.23% without catalyst addition in the present study. In addition, the addition of Fe/Al-pillared bentonite catalyst also improves the quality of pyrolysis-produced oil and promotes the formation of CH4. Fe/Al-pillared bentonite provides acid center in the inner surface, which is beneficial to the cracking reaction of oil molecules in pyrolysis process. The present work implies that Fe/Al-pillared bentonite as addictive holds great potential in industrial pyrolysis of oily sludge.